(1) Field of the Invention
The invention relates to folders in high-speed web-fed rotary printing machines in general and particularly to folders with folding cylinders for producing signatures with various kinds of folds in magazine printing machines and with shiftable gears for driving the transfer and delivery cylinders of such folders for varying the angular velocity of these cylinders.
(2) Description of the Prior Art
Known in the art are folders in magazine-type printing machines with cutting, collecting, folding and delivery cylinders for various kinds of folds, mostly having multiple sets of folding elements in the folding cylinders and having also folding cylinders for so-called double-parallel folds. Some of these folders are arranged for several separate deliveries and for one or two-slow down mechanisms in order to obtain properly laid signatures on the delivery conveyors in high-speed orienting machines. Typical prior art patents of this kind are U.S. pat. Nos. 2,991,995, 3,032,335 and 3,059,921. The U.S. Pat. No. 2,991,995 teaches a folding mechanism for printing machines in which the folding and tucking cylinder has a reduced diameter thereby achieving a "slow-down." U.S. Pat. No. 3,032,335 teaches distributing cylinders of reduced diameter to slow-down the delivery of signatures. The distributing cylinders receive only alternate folded signatures. U.S. Pat. No. 3,059,921 teaches a paper folding machine having variable size primary folding cylinders to achieve a speed match with the printing cylinder.
Several problems turned up with increased production speeds of the magazine presses. One of these problems is a disorderly transfer and delivery of folded signatures, which causes troubles on the conveyors to the bindery, for which a single or even a double slow-down is insufficient for certain products with one or more than one transversal fold. Another problem is the time consuming job to change the speed reducing slow-down mechanism from a greater slowdown to a full speed operation, when it is desired to use the high speed capacity of the printing machine for certain folded products which can be delivered without trouble at the higher speed. Some of the prior art does not have even the facilities for changing the slow-down speed at all.
These and other problems which arise from the use of the higher speeds of modern magazines production printing machines are solved by this invention.